464 Bulletin 47, United States National Museum. 



Coregonus williamsoni cismontanus, JORDAN, Bull. U. S. Fieh Comm., ix, 1889, 49, pi. 9, figs. 8, 9, 

 Horsethief Creek, a tributary of Madison River, Montana. (Coll. E. R. Lucas.) 



757. COREGONUS KENNICOTTI, Milner. 

 (BROAD WHITEFISH ; MUKSUN OF THE RUSSIANS.) 



Head small, 5f; depth about 4f. D. 11; A. 14; scales 10-87 to 90-10. 

 Eye moderate, shorter than snout, 5 in head, 1* in interorbital space. 

 Scales small, adherent, very regularly imbricated. Head very blunt, 

 premaxillaries wide and vertically placed. Mouth inferior, with the 

 high blunt snout but little projecting. Maxillary reaching slightly 

 beyond the vertical from front of eye, its length, measured from its 

 anterior articulation, equal to length of snout, and contained 4| times 

 in the head ( =4 in head when measured from tip of snout); maxillary 

 broadly ovate, apparently slenderer than in C. richardsonii as figured by 

 Giinther, and with different outlines. Preorbital narrow, its greatest 

 width contained 5 times in its length, and 3i times in diameter of eye; 

 width of supraorbital bone f its length. Gill rakers 6 or 7 -f- 14, short 

 and slender, tapering to a slender flexible point, the longest f diameter 

 of pupil. Hyoid bone with a round patch of weak, bristle-like teeth; 

 these are very similar to those found in Stenodus, and are disposed in 

 longitudinal series. Vertical height of head at nape less than length of 

 head by i diameter of eye ; distance from tip of snout to nape i distance 

 from nape to front of dorsal ; front of dorsal nearer snout than base of 

 median caudal rays by length of snout and eye. Adipose fin large, a 

 wide strip at base covered with small, regularly imbricated scales; 

 inserted over last rays of anal, extending but slightly behind last anal 

 ray ; ventrals reaching halfway to front of anal ; height of dorsal equal to 

 length of head without snout. Color must have been very dark in life ; 

 fins all blackish, in spirits, with a bluish tinge; traces of what may 

 have been blackish spots and vermiculations are discernible on basal 

 portion of dorsal and anal fins. The above description from a specimen 

 obtained by Miss Elizabeth Taylor in Great Bear Lake. The type of 

 C. Jcennicotti (No. 8971, Fort Good Hope, British America) possesses the 

 following characters : This specimen is a skin 21 inches long. Length of 

 head 3i inches; tip of snout to end of maxillary i inch; diameter of 

 eye (not orbit) i inch ; length of longest gill raker & inch. Maxillary 

 contained 4^- times in head ; longest gill raker 3 times ; width of pre- 

 orbital 2| times, in eye. Number of gill rakers 7 -f 13. Scales 10-90-10. 



This species seems closely related to Coregonus richardsonii, Giinther, 

 with which it may prove identical. As Dr. Bean has already noticed, 

 Giinther's description includes no account of the gill rakers, which may 

 be long and numerous, as in C. clupeiformis, but indicates a fish with a 

 longer snout, and a broader supplementary maxillary bone. (Gilbert.) 

 Mackenzie and Yukon rivers ; locally abundant. (Named for Robert Ken- 

 nicott, discoverer of the species, one of the first American naturalists to 

 visit Alaska.) 



t Salmo lavaretus, Tar. muchsun, PALLAS, Reise, in, 705, about 1780. 

 ? Salmo mwfcswn, P AS, Zoogr. Rosso-Asiat., in, 398, 1811. 



